Id say a 10 pound test mono is a good start., I use stren, but you dont need to, you could use berkley xl as well its a good line too.
Now this next paragraph is very important
When it comes to spooling the line you may want to search "spooling spinning reels" or "re-spooling spinning reels" on this site,....as its a bit more involved than one would think,... and im pretty sure Glenn would have that here.,..
The idea is not to twist the line all up when spooling., its easy to do, and will ruin your 1st outing quickly..,..If the search doesnt work out,...you can personal message me here,.. and I'll type it out for you.